Oh Poop!

Question
My horse eats poop.

But only in the winter. Last year I was panicked to find almost no manure in his stall when he had to stay in longer than normal. Then I noticed him trying to bite off frozen manure balls in the paddock.

He doesn't show any interest in manure during the warmer months. I have taken an in depth nutrition course but we had never covered poop-eaters and I didn't notice he ate manure until after the fact. He is receiving all the nutrients the NRC calls for and is health.

What can I do? He's a 9 year old thoroughbred so he's not a foal eating poop.

Answer
Hi Ali,

Thanks for your question.  There are 2 possible reasons that might explain why your horse is eating poop.

Some horses will eat manure, especially in their stalls, to mimic natural foraging behavior.  It's a stereotypy (bad habit) that they develop to imitate a normal environment, where they would spend up to 18 hours a day grazing.  They will eat manure more in their stalls if they are left long periods without anything to eat, especially forages.  Horses should not go more than 4 hours without access to food as it can lead to the development of ulcers, and the development of this kind of stereotypy. It would help to ensure that your horse has enough feed, when inside, to keep him foraging.  If you don't want to feed more hay inside, split your feedings up into fewer/smaller meals with an extra trip to the barn at night.

Some suggest that adult horses will eat manure in an attempt to increase their vitamin B intake.  The bacteria in the hindgut of the horse produce B vitamins as a by-product of fermenting forages, and this is how a horse would naturally get most of it's B vitamins.  But when there is a disruption in the function of the hindgut bacteria, fewer B vitamins are produced and the horse goes into a deficit...and eating the manure is an attempt to reclaim any B vitamins lost in the manure.  Along that same line of thought, it could be argued that the adult horse is eating manure to help re-populate the hindgut with beneficial bacteria (as this is the reason why newborn horses do it) that may have been lost...but in reality, it would be a futile hobby for the adult horse.  Either way, feeding a good quality pre-biotic will help stabilize the hindgut and both help the beneficial bacteria thrive, and increase the amount of B vitamins they produce.  

Unfortunately, eating manure can become a lasting habit even once the source of the stereotypy has been rectified.  It is not one of the worst habits they can develop, but anything you can do to keep him busy at other tasks would help him.

I hope that helps.

Thanks, Corlena